疏松砂岩油藏水平井防砂筛管优选和防砂精度优化

南海东部珠江口盆地疏松砂岩油藏埋藏浅，泥质含量高，易出砂。为优选适用于该油田水平井的防砂筛管，采用实尺寸筛管防砂物理模拟实验装置，结合该油田储层特征（d₅₀=250 μm，非均匀系数3.17，泥质12%）和实际工况，进行了不同类型防砂筛管的防砂物理模拟实验，通过测定不同防砂精度（150、200、250、300 μm）条件下的流量、压降、油中含砂量、产出砂粒径等参数，系统评价了改进型星孔复合筛管及其他3种不同结构的金属网布复合筛管防砂性能、抗堵塞性能和综合性能。结果表明:金属网布复合筛管Ⅱ（保护套+斜纹网+双层密纹网+斜纹网+基管）和金属网布复合筛管Ⅰ（保护套+斜纹网+三层密纹网+斜纹网+基管）防砂性能、抗堵塞性能以及综合性能指标都较高，适合作为南海东部珠江口盆地疏松细~中砂岩油藏高含水期水平井防砂筛管，并推荐油田防砂精度为200~250 μm。该研究可为该油田进行防砂方案设计提供依据。

Selection and sand control precision optimization of sand control screen for horizontal wells in unconsolidated sandstone oil reservoirs

Unconsolidated sandstone oil reservoirs in the Pearl River Mouth Basin in the east of the South China Sea are characterized by shallow burial depth, high shale content and easy sand production. In order to select the sand control screen suitable for the horizontal wells in this oilfield, physical simulation experiments of sand control were carried out on different types of sand control screens by using the full-scale physical simulation experiment device of sand control screen, based on the reservoir characteristics (d₅₀=250 μm, heterogeneity coefficient 3.17, and shale content 12%) and actual working conditions in this oilfield. After the flow rate, pressure drop, sand content of oil and particle size of produced sand at different sand control precisions (150, 200, 250 and 300 μm) were measured, the modified star-hole composite screen and three metal-mesh composite screens with different structures were evaluated systematically from the aspects of sand control property, anti-blocking capacity and overall performance. It is indicated that metal-mesh composite screen II (protective sleeve + square hole net + dual-layer dense net + square hole net + base tube) and metal-mesh composite screen I (protective sleeve + square hole net + three-layer dense net + square hole net + base tube) are better in the indicators of sand control property, anti-blocking capacity and overall performance, and they are suitable to act as the sand control screen of horizontal wells in fine-moderate unconsolidated sandstone oil reservoirs with high water cut in the Pearl River Mouth Basin in the east of the South China Sea. And it is recommended to set the sand control precision at 200-250 μm. The research results provide the basis for the design of sand control scheme of this oilfield.